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import os
import shlex
import subprocess

import IECore

import Gaffer
import GafferDispatch

class SystemCommand( GafferDispatch.TaskNode ) :

	def __init__( self, name = "SystemCommand" ) :

		GafferDispatch.TaskNode.__init__( self, name )

		self["command"] = Gaffer.StringPlug()
		self["shell"] = Gaffer.BoolPlug( defaultValue = True )
		self["substitutions"] = Gaffer.CompoundDataPlug()
		self["environmentVariables"] = Gaffer.CompoundDataPlug()

	def hash( self, context ) :

		command = self["command"].getValue()
		if command == "" :
			return IECore.MurmurHash()

		h = GafferDispatch.TaskNode.hash( self, context )

		h.append( command )
		self["substitutions"].hash( h )
		self["shell"].hash( h )
		self["environmentVariables"].hash( h )

		return h

	def execute( self ) :

		substitutions = IECore.CompoundData()
		self["substitutions"].fillCompoundData( substitutions )
		substitutions = { key : str( value ) for ( key, value ) in substitutions.items() }

		command = self["command"].getValue()
		command = command.format( **substitutions )

		env = Gaffer.environment()
		environmentVariables = IECore.CompoundData()
		self["environmentVariables"].fillCompoundData( environmentVariables )
		for name, value in environmentVariables.items() :
			env[name] = str( value )

		useShell = self["shell"].getValue()
		if useShell == False :
			command = shlex.split( command )

		subprocess.check_call( command, shell = useShell, env = env )

IECore.registerRunTimeTyped( SystemCommand, typeName = "GafferDispatch::SystemCommand" )

Gaffer.Metadata.registerValue( SystemCommand, "dispatcher:allowIsolation", True )
